Dodge 2007 Ram Chassis Cab - Manual (Page 352)

The electrical connections are all complete to the vehicle
but you must mate the harness to a trailer connector.
Refer to the following illustrations.
Towing Tips
Before setting out on a trip, practice turning, stopping
and backing the trailer in an area away from heavy
traffic.
4 - Pin Connector
7- Pin Connector
352 STARTING AND OPERATING